Development of hyperpolarized noble gas MRI

Area of Science:

• Medical Imaging
• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Noble Gas Physics

Background:

• Magnetic Resonance Imaging (MRI) faces Signal-to-Noise Ratio (SNR) limitations for certain diagnostic applications.
• Hyperpolarization techniques significantly enhance the MR signal of noble gases like 129Xe and 3He.
• 129Xe's solubility in lipids and blood offers potential for imaging tissues beyond the lung gas space.

Purpose of the Study:

• To explore the application of hyperpolarized 129Xe MRI (HypX-MRI) as a novel diagnostic technique.
• To overcome SNR challenges in in vivo MR imaging using 129Xe.
• To investigate the potential of HypX-MRI for studying lipid-rich tissues and brain function.

Main Methods:

• Utilized hyperpolarized 129Xe and 3He for Magnetic Resonance Imaging (MRI) and spectroscopy.
• Adapted hyperpolarization techniques pioneered by William Happer.
• Acquired dissolved-phase 129Xe tissue spectra and chemical shift images in rodents and humans.
• Obtained lung gas images of rodents and humans using hyperpolarized 129Xe.

Main Results:

• Hyperpolarized 129Xe MRI demonstrated enhanced detectability, addressing SNR limitations.
• Published images of excised mouse lungs marked the advent of hyperpolarized noble-gas MRI.
• Achieved dissolved-phase 129Xe tissue spectra and chemical shift images in the thorax and head.
• Successfully obtained lung gas 129Xe images in rodents and humans.

Conclusions:

• Hyperpolarized 129Xe MRI is a promising new diagnostic technique with potential for high-resolution imaging.
• HypX-MRI can elucidate lung structure-function relationships and aid in diagnosing pulmonary diseases.
• The technique's ability to image lipid-rich tissues and brain function opens new avenues for neurological and physiological research.